--- /dev/null
+<?php
+
+/**
+ * @file
+ * Provides hook implementations for Layout Test.
+ */
+
+/**
+ * Implements hook_preprocess_HOOK() for layout templates.
+ */
+function template_preprocess_layout_test_2col(&$variables) {
+ $variables['region_attributes']['left']->addClass('class-added-by-preprocess');
+}